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authorJames Smart <jsmart2021@gmail.com>2018-09-10 10:30:45 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-13 11:15:00 -0800
commit7f4b23ed2cdb5ba7a6edf002ea9cf0f5f684dca5 (patch)
tree43e14e313c751766caeda2c98c001a7e64e6ff06 /drivers/scsi
parentadfbc0d10727027a17fb1784548245cda2fae30e (diff)
scsi: lpfc: Correct soft lockup when running mds diagnostics
[ Upstream commit 0ef01a2d95fd62bb4f536e7ce4d5e8e74b97a244 ] When running an mds diagnostic that passes frames with the switch, soft lockups are detected. The driver is in a CQE processing loop and has sufficient amount of traffic that it never exits the ring processing routine, thus the "lockup". Cap the number of elements in the work processing routine to 64 elements. This ensures that the cpu will be given up and the handler reschedule to process additional items. Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com> Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/lpfc/lpfc_sli.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index dc83498024dc..24b6e56f6e97 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -3585,6 +3585,7 @@ lpfc_sli_handle_slow_ring_event_s4(struct lpfc_hba *phba,
struct hbq_dmabuf *dmabuf;
struct lpfc_cq_event *cq_event;
unsigned long iflag;
+ int count = 0;
spin_lock_irqsave(&phba->hbalock, iflag);
phba->hba_flag &= ~HBA_SP_QUEUE_EVT;
@@ -3606,16 +3607,22 @@ lpfc_sli_handle_slow_ring_event_s4(struct lpfc_hba *phba,
if (irspiocbq)
lpfc_sli_sp_handle_rspiocb(phba, pring,
irspiocbq);
+ count++;
break;
case CQE_CODE_RECEIVE:
case CQE_CODE_RECEIVE_V1:
dmabuf = container_of(cq_event, struct hbq_dmabuf,
cq_event);
lpfc_sli4_handle_received_buffer(phba, dmabuf);
+ count++;
break;
default:
break;
}
+
+ /* Limit the number of events to 64 to avoid soft lockups */
+ if (count == 64)
+ break;
}
}